A polarizing plate is applied to various display devices such as a liquid crystal display and an organic electroluminescent device. Recently, the mainly used polarizing plate is in a form where a protection film is laminated on one surface or both surfaces of a PVA polarizer manufactured by alignment by a method for dyeing iodine and/or dichromatic dyes on a polyvinyl alcohol (hereinafter, PVA)-based film, and then cross-linking the iodine and/or dichromatic dyes by using boric acid and the like, followed by elongation.
Meanwhile, there is a current trend toward increasing slimness of the display device, and in order to implement a large screen, the display device has been developed toward a trend where thicknesses of a bezel portion and an edge where the screen is not displayed are minimized. Further, in order to implement various functions, parts such as cameras tend to be equipped in a display device, and in consideration of a design factor, efforts of providing various colors to a product logo or an edge region or decoloring the product logo or the edge region have been made.
However, in the case of a polarizing plate in the related art, since an entire region of the polarizing plate is dyed with iodine and/or dichromatic dyes, the polarizing plate has a dark black color, and as a result, there are problems in that it is difficult to provide various colors to a display device, and particularly, in the case where the polarizing plate is positioned on parts such as cameras, 50% or more of the quantity of light is absorbed by the polarizing plate to reduce visibility of a camera lens.
In order to solve the problems, a method for physically removing a portion of the polarizing plate, which covers the camera lens, by piercing a hole (boring) in the portion of the polarizing plate by a method such as punching and cutting has been commercialized.
However, the aforementioned physical method degrades an appearance of the image display, and the polarizing plate may be damaged due to characteristics of a process of piercing the hole. Meanwhile, in order to prevent damage such as tearing of the polarizing plate, a bored portion of the polarizing plate should be formed in a region sufficiently far away from a corner, and as a result, there is a problem in that in the case when the polarizing plate is applied, the bezel portion of the image display is relatively widened which deviates from a current narrow bezel design trend of the image display. Further, there is a problem in that in the case where a camera module is equipped in the bored portion of the polarizing plate, as described above, since the camera lens is exposed to the outside, the camera lens is easily contaminated and damaged when the camera lens is used over a long period of time.
Therefore, in order to overcome the aforementioned problems, a development of a new process of providing a method for decoloring a local region of a polarizer without boring to form a depolarization region, and simultaneously, suppressing fine wrinkles and surface roughness that may occur in the depolarization region to reduce a haze is needed.